CA1036477A - Chair reclining mechanism - Google Patents
Chair reclining mechanismInfo
- Publication number
- CA1036477A CA1036477A CA213,794A CA213794A CA1036477A CA 1036477 A CA1036477 A CA 1036477A CA 213794 A CA213794 A CA 213794A CA 1036477 A CA1036477 A CA 1036477A
- Authority
- CA
- Canada
- Prior art keywords
- seat
- base
- link
- lever
- chair
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000007246 mechanism Effects 0.000 title abstract description 7
- 230000033001 locomotion Effects 0.000 claims abstract description 33
- 230000001133 acceleration Effects 0.000 abstract description 2
- 230000009471 action Effects 0.000 description 4
- 230000037396 body weight Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 238000007493 shaping process Methods 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 241000283986 Lepus Species 0.000 description 1
- 229910000746 Structural steel Inorganic materials 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 210000003127 knee Anatomy 0.000 description 1
- 210000002414 leg Anatomy 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000003387 muscular Effects 0.000 description 1
- 239000011295 pitch Substances 0.000 description 1
- 230000035807 sensation Effects 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47C—CHAIRS; SOFAS; BEDS
- A47C1/00—Chairs adapted for special purposes
- A47C1/02—Reclining or easy chairs
- A47C1/031—Reclining or easy chairs having coupled concurrently adjustable supporting parts
- A47C1/032—Reclining or easy chairs having coupled concurrently adjustable supporting parts the parts being movably-coupled seat and back-rest
Landscapes
- Health & Medical Sciences (AREA)
- Dentistry (AREA)
- General Health & Medical Sciences (AREA)
- Chairs For Special Purposes, Such As Reclining Chairs (AREA)
- Chairs Characterized By Structure (AREA)
Abstract
ABSTRACT
A reclining chair mechanism having its back supported for reclining rotation and forward shifting movement relative to a base, and its seat supported by overslung links which elevate the seat front rapidly upon forward shifting movement of the seat by the reclining rotation of the back, and wherein the seat is connected to the back in a manner such as to maintain the lever-age of the occupant's weight upon the seat to counteract the leverage of the occupant's weight upon the back to prevent accel-eration in the reclining movement and to maintain the chair in balance in various degrees of recline.
A reclining chair mechanism having its back supported for reclining rotation and forward shifting movement relative to a base, and its seat supported by overslung links which elevate the seat front rapidly upon forward shifting movement of the seat by the reclining rotation of the back, and wherein the seat is connected to the back in a manner such as to maintain the lever-age of the occupant's weight upon the seat to counteract the leverage of the occupant's weight upon the back to prevent accel-eration in the reclining movement and to maintain the chair in balance in various degrees of recline.
Description
~36~77 Our invention relates to reclining chairs, and more specifically to linkaye mechanism for correlatiny the move-ment of the chair back and chair seat with respect to each other and to the common base upon which they are supported.
~eclining chairs, as such, are an old and well-de-veloped art that teaches many arranyements for correlatiny the relative movement of seat and back to each other, as well as to other movable members and to the chair bases upon which they are supported. The present invention is concerned, how-ever, with a linkage of the general kind described which has distinct advantages over those earlier proposed for similar purpose in that it accomplishes previously desired objectives without the disadvantages that heretofore have been associated with the attainment of these objectives.
In particular, the prompt elevation of the forward edge of the seat as an incident ~o initial reçlining movement of the back has-been recognized as a desired objective, and has been earlier attained by the overslung linkage which is a component part of this invention. However, the mechanisms heretofore developed which have incorporated overslung seat supporting linkages have-usually also been characterized by a rapid shift of influence of the occupant's body weight from the portion of his weight pressing down on the seat to that portion pressing rearward and downward against the back, with the undesirable development o~ rearward acceleration, i.e., an uncomfortable and even alarming "falling-away" sensation.
Approaching from another-tackj the prior art also discloses underslung seat mechanisms, which likewise elevate the seat as an incident to reclining movement of the back, and in such mechanisms, indeed, the initial forward and only then upward movement of the seat increases the effect of the occupant's weight upon the seatj and more than counteracts --1-- .
~03f~77 the effect of that portion of his weiyht beariny rearwardly and downwardly upon the back. With undersluny support of the seat section, however, the elevation of the seat ln~ident to the reclining of the back is much delayed as compared with that of the overslung linkage, and full recline of the back can re-quire more effort to maintain than is conducive to repose.
Wherefore, a principal object of our invention is to utilize fully the advantage of the oversluny seat-support link-age, viz., the rapid rise of the seat, particularly a-t the front edge, upon initial recline of the back, but to simul-taneously obviate the difficulties experienced in earlier such attempts, viz., the rapid transfer of influence to the portion of the occupant's body weiyht exerted ayainst the chair back.
In short, we propose by our invention to have the ad-vantage of the fast-rising seat-elevating movement afforded by an overslung seat-support linkage, while at the same time maintaining a balance between the respective influences of body weight upon the seat and upon the back to maintain the chair in reasonable balance at any position of recline with-out requiring the auxiliary or artificial motion~retarderswhich usually increase the muscular effort required to change the attitude of the reclinin~ chair.
It is our further object to provide a reclining chair which attains the above objective by a movement of the seat and lower portion of the backrest forwardly on the chair base, which has the further desirable result of maintaining the center of gravity of the chair and its occupant more or less fixed throughout the reclininy movement, as well as mini-mizing the wall or other clearance required behind the chair to permit the same to be reclined.
Our still further object is to provide a linkage of the kind described in which the respective linkage members ~V3~ 77 are under load in all positions 50 that inevitable wéar and consequent loosening of the riveted pivotal connections of the linkage are not made evident by rattliny, as sometirnes occurs when recline linkages are used on rocking bases in so-called "rocker-recliner" chairs.
Our invention, and its attainment of the foregoincJ
objectives, will be evident from the followiny specification, taken in conjunction with the accompanyiny drawings in which ~ FIGURE 1 is a perspective view of our recline linkage as seen from a rear quarter with portions of the seat bracket broken away to better illustrate the remaining parts;
FIGURE 1 A is a perspective view of only the seat bracket of the linkage, shown in full immediately above its position in Figure l so that its form will be clear;
FIGURE 1 B is an enlarged perspective view of one element of the linkage shown in the same attitude it assumes in Figure l but removed from context for clearer illustration;
- FIGURE ~ is a diagrammatic side elevation of the link-.
age in sitting position, showing its position in the chair sug-- 20 gested by the broken outline; and ~ FIGURE 3 is a similar diagrammatic side elevation of the linkage (and chair) in recline.
Figure l illustrates a linkage in accordance with the invention, one of two such linkages, each a mirror image of the other, required for each chair. The linkage is attached to the base frame l0 of a chair illustrated in broken outline in the drawings, by means of a base bracket 12, and the chair back 14 is mounted on the base by means of a back-support bracket 16 whose path of movement relative to the base bracket is determined by a pair of links 18 and 20. The length and angularity of the back support links 18 and 20 are such that the rotation of the chair back 14 by the reclining movement - .
... .
~lU3~9~77 moves the lower end of,the back forwardly of ~he base through a fixed path incident to such rotation.
The seat 22 of the chair is carried on a seat bracket 2a .,, which is connected for movement conjointly with the back. The seat is supported toward its front end by a link 26 pivoted to the seat bracket 24 and to the base bracket 12 and is supported adjacent its rear end hy its pivotal connection to a bell crank lever 28 which,is itsel pivotally mounted upon the forward back support link 20, and controlled in its angularity relative thereto by a control link 30 pivoted respectively to the bell crank lever 28 and to the back support bracket 16. The controlled action of the bell crank lever 28 incident to reclining movement of the back is to thrust the seat forwardly, as indicated by the tran-sition from Figure 2 to Figure 3. Coincident therewith, the upper end of the seat support link 26 swings upwardly as well as forwardly, and pitches the front end of the seat upwardly.
The forward motion of the seat bracket 24 caused by its pivotal attachment to the beLl crank lever 28 is the re-sult of a dual movement, viz., the forward rotation of the .
forward back-support link 20, and the concurrent movement of the bell crank lever 28 on the link 20 counterclockwise tas seen~in the drawings) caused in turn by the counterclockwise rQtation of the back-support bracket 16 relative to the for-ward back-support link 20 and transmitted to the bell crank 28 through the control link 30. As this movement proceeds~
the leverage of the occupant's weight upon the seat 22, ex-erted upon the backrest bracket L6 through the bell crank lever 28 and the control link 30, is multiplied, and counter-acts the influence of the rearward pressure of the rgreater body weight of the upper portion of the body upon the chair back 14 during the recline movement.
When it becomes understood that the function of the . . . _ _ .
103f~4~77 bell crank lever 28 is to increase the moment o~ the seat weight in order to counterbalance of the increasing mom~nt of the back weight as the back reclines, and ~hat this counter-moment is applied in the preferred embodiment illustrated by forces applied both to the back-support bracket 16 (throuyh the control link 30) and to the forward back-support link 20 (through the bell crank 28), it becomes evident that the countermoment might also be applied by the suitable applica-tion of force to either of the back-support links 20 and 18 alone, or indeed to the back rest itself.
For example, we ha~e contemplated the inversion and ,, re-shaping of the bell crank 28, and its connection by means o a control link, such as the link 30, to the base bracket 12 instead~of to the back-support bracket 16. In su~h case, the control link would be in tension i~stead of ln compres sion, and the counterbalancing effect of the seat weight would be applied as a force opposing the forward rotation of the forward back-support link 20. However, we prefer the illustrated,embodiment because as may be appreciated from Fig. 3, the toggle formed by the back support bracket 16 and the rearward back-support link 18 approaches alignment in the full recline position. In these circumstances, the attach-ment of the control link 30 to the back-support bracket 16, - as illustrated, applie~ a counter-force directly to the back-support bracket 16 to break the togg,le "knee", and assist the return of the back rest to thé upright position.
We conceive it also possible to connect the control link 30 to the rearmost back-support link 18, again with some , re-shaping of the lever 28 to achieve the desired result.
On the other hand, the application of a countermoment directly to the back rest alone, as by pivoting the rearward portion of the seat directly upon an extension of the back-,, -5-~V3t;4t77 support bracket 16, while effective in counterhalancing the back in the setting of an overslung seat-suppart linkage, is undesirable for other overriding reasons, viz., because the rearward movement of the lower end of the back away from the seat incident to recline is undesirable for its "shirt-tail.pulling" effect and also for its failure to provide the lower lumbar support that results from the illustrated linkaye, in which the lower supporting surface of the back rest move~
but little forwardly or rearwardly o the seat during the reclining movement.
Referring in,greater detail to the drawings and par-ticularly Figure.l, it will be seen that-the base bracke~,12 is essentially a length of angle iron with its vertical.flange directed upwardly on the lnner~side of the bracket, ahd having lS at,~i~s rear end an~up~ardly inclined outrigger extension 32.
The horizontal flange of the base bracket 12 is provided with a number...of anchori,n~ holes,34 for securing the.same to a wooden base by means of any suitable fasteners, preferably screws. In each of the drawings, the linkage~is.depicted-:as mounted upon a fixed chair base 10, suggesting its application to an ordinary redlining chair, but it should be understood that the,linkaqe~is equally applicable:to so-called "rocker-recliners" in which case ~he base mounting bracket,12 is secured in the,same f,ashion t,o the racker element instead, of to a fixed base as the drawing~ indicate.
The aforementioned outrigger 32 of thæ base bracket, 12 provides an appropriately.positioned point of attachment for the lower end of the rear back-support link 18~ the upper end of which is suitably pivoted to the lower end of the back-support bracket 16. The forward back-support link 20 is bommerang shaped and-pivote~ at the juncture of its two arms to the upstanding flange of the base bracket 12, and at the 1~}3~4~7 upper end of its rearwardly and upwardly extendin-J arm to ~he lower forward end of the back-support bracket 16. It will be apparent that the two links 18 and 20, constituting together with the base bracket 12 and the back-suppoxt bracket 16 a four-bar trapezoidal linkage, fully determine the path of movement o the back-support bracket 16, which a~ sh~wn by comparison o ~igures 2 and 3, moves forwardly relative to the base bracket 12 as it is rotated counterclockwise by the reclining movement.
- As shown especially in Figure 1, the vertical flanye of the base bracket 12 and the side plate of the back sup-port bracket 16 are in the same plane, the back support links 18 and 20 beLng mounted on the inside surfaces of ~ those brackets. The other, shorter arm 36 of the bommerang- -shaped back-support link 20 engages a stop plate 37 secured ~ to ~h~ under~i~e of the hase bracket 12, and thus aetermines ; the upright or sittLng position of the linkage.
The back-support bracket 16~has an inwardly eXtending ~ flange 38 to provide a mounting seat for the frame of the backrest 1~, holes 40 being provided therein to secure the - back to its suppor~ing bracket by means of screws. The Iowar -~
end of the flange 38, by its contact with the rear back sup-port link l8, provides a stop to determine the fully reclined position (Figure 3).
:
~ ~ The seat support bracket-24 is a downwardly-open channel in its forward portion, thus providing opposed flanges ~or mounting the operating li~kage o a footrest 42. Such .
linkage, ~eing irrelevant to the subject matter shown and claimed, is omitted, and may be any suitable footrest support mechanism operated either by the reclining action of the seat and back, or by separate lever action, as may be desired in a particular application.
r~ .
:; ~7- .
~36~r~7 The rearward, angle portion of ~hc sea~ bracket 24 ¢Fic~ure 1 A) includes a depending vertical inner flange 4~ of yradually increasing depth from front to rear, providiny forwardly of its mid point a ConYenient site for the pivotal atkachment of the forward support link 26. For reasons not relevant here, the : flange 44 has a circular boss stamped outwardly therefrom so that the pivot rivet at the upper end of the link 26 may be flush with the forward surface.of the flange. The more rearward deepest portion of the flange 44 is the point of the pivotal at-tachment of the seat bracket to the lower orward pivot of thebell crank lever 28, while rearwardly of its pivotal attachment to the bell crank, the vertical flange 44 of the seat support bracket recedes upwardly to.a depth commensurate with its , horizontal flange.
The forward portion of the seat bracket 24, as earlier noted, is an inverted channel-whose outer flange 46 is pierced aoaxially with the rivet hole for the:upper pivot of the link 26, to provide a work hole 48 large enough for access by the riveting tool.
20 - Because the seat bracket 24 is mounted outwardly of the ~-baak-support links 18 and 20, and outwardl~ of the bell crank 28 and the control link 30, its rearward portion is shown in broken outline in several of the drawings in order not to obscure those elements of the-linkage.
In order to;provide the necessary moming clearances for the action of the several m~bers of the linkage in the transition from Figure 2 to Flgure 3, relief in depth is provided by offsets in the bell crank lever 28, in the con-trol link 30 as well. Specifically as noted particularly in Figure 1 B~ the body of the bell crank lever 28, a triangular stamping, occupies three planes. At the site of its pivotal attachment to the seat brackPt 24, it is embossed outwardl~
, ......................................................................... ~ ~,,.
~036~77 as at S0, and at the site of its pivotal atkachment to the for-ward back support link 20, it is el~ossed inwardl-y as at 52, leaving its third pivot site 54 in the mid-plane. Clearance for the movement of the'control link 30 is thus provided between the vertical flange 44 of the seat bracket and the ~or~ard back support link 20. The control link 30 itsel is o~set at its upper end to provide clearancé for its passaye over the head o~
the upper pivot rivet of-the back-support link 20.
,~ Because oP the balance achieved in this linkage, it, i5 possible to construct the upholstered seat and arms for at-tachment as an integral unit to the seat bracket 2~. This is pa,rticularly desirable in the rocker-recliner chairs for it , .
not only eliminates the wear and noise resulting.,from movement of the seat within,and rèlative to the arm frames, it also lends .
,~ 15 great'er flexibility of styling as contrasted to chairs of ~ current manufacture having a two-phase reclining movement, - , ,:
i.e., a first rearward shifting of the seat to extend the leg ,- rest to an intermediate so-cailed'"TV" position, essentially ~ without substantially reclining movement of the back. Such ~chairs, by~requiring fixed arm rests against which the oc-cupant can push hLmself and the seat rearwardly, are lim~ted 'in their styling capabilities inasmuch as they cannot satis-~; ~factorily use a T-shaped seat cushion.
~- ~ As earlier indicated, the sitting position of the,, chair is determinéd by the engagement of the,lower arm 36 'of,the forward, boomerang back suppbrt link 20 with the stop ~platP 37 secured to the hori~ontal flange of the base bracket 12. This is shown both in Figure 1 and Figure 2. Particular-ly from Figure 2 it will be,noticed that the support link 26 for the seat is lnclined upwardi~ ,and rearwardly in sitting position so that the occupant'~ ~eight,upon the seat main-tains a compre~sive loading not only upon the support link 26 ,~ ~
- : . .. , . . ~
::~
- . _ g _ , __ -, ~'V3~4q7 , of thç se,at, but also upo,n the,control link 30. It,will further be apparent that each one,of the pivots of the linkaye likewise remains under load in,every conceivable position the~linkage may occup~. This constant loading has tke advantage, as earlier in-~5 dicated, of eliminating clicking noise in the linkage when thesame is used in a rockér-recliner~ i.e./ when the linkage in the position shown in Figure 2 is-rocked back,and forth without rela-~, .
~ tive,movement,of the seat an~ ba¢k of the chair.
, ~, i ~, , , ~ Further with regard to Figures 2 and 3, it is apparent '~10 that as the,:back,l~ is reclinedi its ~ower end, being immediately : adjacent to the ba~k support bracke~.16, moves,forwardly, as doesthe seat.. Th'e center.-of gra~ity of the occupant, different of . course in person$ of dif,ferent stature/ is usually located in the : . lower abdome~.. The position o~ that center,.asi may be appre-cia~ed bY comparison of ~igure$-2 an~ 3, will remain,relatively unchanged between the sitting and the fully reclined positions, and in intermediate.positions a~ well...This tends to provide good.inherent balance,wi~hout the need either o counterbalancing ~ springs,.or of motion-retarders or snubberst such,as are often-: '2Q required either to compensate for over-shifting of body weight,, ~:or to provide artificial retardation,for movement that would ' : otherwise be unduly accçle~ated or abrupt. ~ ",~
The features.of ou~ invention beleived new and'patent-abl~ are-set forth in the'appended claims~
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- : . .
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: ' . ' ~, ~,' ' . . , ::
' - . . : ,~ ~ . . :
~ 1 0
~eclining chairs, as such, are an old and well-de-veloped art that teaches many arranyements for correlatiny the relative movement of seat and back to each other, as well as to other movable members and to the chair bases upon which they are supported. The present invention is concerned, how-ever, with a linkage of the general kind described which has distinct advantages over those earlier proposed for similar purpose in that it accomplishes previously desired objectives without the disadvantages that heretofore have been associated with the attainment of these objectives.
In particular, the prompt elevation of the forward edge of the seat as an incident ~o initial reçlining movement of the back has-been recognized as a desired objective, and has been earlier attained by the overslung linkage which is a component part of this invention. However, the mechanisms heretofore developed which have incorporated overslung seat supporting linkages have-usually also been characterized by a rapid shift of influence of the occupant's body weight from the portion of his weight pressing down on the seat to that portion pressing rearward and downward against the back, with the undesirable development o~ rearward acceleration, i.e., an uncomfortable and even alarming "falling-away" sensation.
Approaching from another-tackj the prior art also discloses underslung seat mechanisms, which likewise elevate the seat as an incident to reclining movement of the back, and in such mechanisms, indeed, the initial forward and only then upward movement of the seat increases the effect of the occupant's weight upon the seatj and more than counteracts --1-- .
~03f~77 the effect of that portion of his weiyht beariny rearwardly and downwardly upon the back. With undersluny support of the seat section, however, the elevation of the seat ln~ident to the reclining of the back is much delayed as compared with that of the overslung linkage, and full recline of the back can re-quire more effort to maintain than is conducive to repose.
Wherefore, a principal object of our invention is to utilize fully the advantage of the oversluny seat-support link-age, viz., the rapid rise of the seat, particularly a-t the front edge, upon initial recline of the back, but to simul-taneously obviate the difficulties experienced in earlier such attempts, viz., the rapid transfer of influence to the portion of the occupant's body weiyht exerted ayainst the chair back.
In short, we propose by our invention to have the ad-vantage of the fast-rising seat-elevating movement afforded by an overslung seat-support linkage, while at the same time maintaining a balance between the respective influences of body weight upon the seat and upon the back to maintain the chair in reasonable balance at any position of recline with-out requiring the auxiliary or artificial motion~retarderswhich usually increase the muscular effort required to change the attitude of the reclinin~ chair.
It is our further object to provide a reclining chair which attains the above objective by a movement of the seat and lower portion of the backrest forwardly on the chair base, which has the further desirable result of maintaining the center of gravity of the chair and its occupant more or less fixed throughout the reclininy movement, as well as mini-mizing the wall or other clearance required behind the chair to permit the same to be reclined.
Our still further object is to provide a linkage of the kind described in which the respective linkage members ~V3~ 77 are under load in all positions 50 that inevitable wéar and consequent loosening of the riveted pivotal connections of the linkage are not made evident by rattliny, as sometirnes occurs when recline linkages are used on rocking bases in so-called "rocker-recliner" chairs.
Our invention, and its attainment of the foregoincJ
objectives, will be evident from the followiny specification, taken in conjunction with the accompanyiny drawings in which ~ FIGURE 1 is a perspective view of our recline linkage as seen from a rear quarter with portions of the seat bracket broken away to better illustrate the remaining parts;
FIGURE 1 A is a perspective view of only the seat bracket of the linkage, shown in full immediately above its position in Figure l so that its form will be clear;
FIGURE 1 B is an enlarged perspective view of one element of the linkage shown in the same attitude it assumes in Figure l but removed from context for clearer illustration;
- FIGURE ~ is a diagrammatic side elevation of the link-.
age in sitting position, showing its position in the chair sug-- 20 gested by the broken outline; and ~ FIGURE 3 is a similar diagrammatic side elevation of the linkage (and chair) in recline.
Figure l illustrates a linkage in accordance with the invention, one of two such linkages, each a mirror image of the other, required for each chair. The linkage is attached to the base frame l0 of a chair illustrated in broken outline in the drawings, by means of a base bracket 12, and the chair back 14 is mounted on the base by means of a back-support bracket 16 whose path of movement relative to the base bracket is determined by a pair of links 18 and 20. The length and angularity of the back support links 18 and 20 are such that the rotation of the chair back 14 by the reclining movement - .
... .
~lU3~9~77 moves the lower end of,the back forwardly of ~he base through a fixed path incident to such rotation.
The seat 22 of the chair is carried on a seat bracket 2a .,, which is connected for movement conjointly with the back. The seat is supported toward its front end by a link 26 pivoted to the seat bracket 24 and to the base bracket 12 and is supported adjacent its rear end hy its pivotal connection to a bell crank lever 28 which,is itsel pivotally mounted upon the forward back support link 20, and controlled in its angularity relative thereto by a control link 30 pivoted respectively to the bell crank lever 28 and to the back support bracket 16. The controlled action of the bell crank lever 28 incident to reclining movement of the back is to thrust the seat forwardly, as indicated by the tran-sition from Figure 2 to Figure 3. Coincident therewith, the upper end of the seat support link 26 swings upwardly as well as forwardly, and pitches the front end of the seat upwardly.
The forward motion of the seat bracket 24 caused by its pivotal attachment to the beLl crank lever 28 is the re-sult of a dual movement, viz., the forward rotation of the .
forward back-support link 20, and the concurrent movement of the bell crank lever 28 on the link 20 counterclockwise tas seen~in the drawings) caused in turn by the counterclockwise rQtation of the back-support bracket 16 relative to the for-ward back-support link 20 and transmitted to the bell crank 28 through the control link 30. As this movement proceeds~
the leverage of the occupant's weight upon the seat 22, ex-erted upon the backrest bracket L6 through the bell crank lever 28 and the control link 30, is multiplied, and counter-acts the influence of the rearward pressure of the rgreater body weight of the upper portion of the body upon the chair back 14 during the recline movement.
When it becomes understood that the function of the . . . _ _ .
103f~4~77 bell crank lever 28 is to increase the moment o~ the seat weight in order to counterbalance of the increasing mom~nt of the back weight as the back reclines, and ~hat this counter-moment is applied in the preferred embodiment illustrated by forces applied both to the back-support bracket 16 (throuyh the control link 30) and to the forward back-support link 20 (through the bell crank 28), it becomes evident that the countermoment might also be applied by the suitable applica-tion of force to either of the back-support links 20 and 18 alone, or indeed to the back rest itself.
For example, we ha~e contemplated the inversion and ,, re-shaping of the bell crank 28, and its connection by means o a control link, such as the link 30, to the base bracket 12 instead~of to the back-support bracket 16. In su~h case, the control link would be in tension i~stead of ln compres sion, and the counterbalancing effect of the seat weight would be applied as a force opposing the forward rotation of the forward back-support link 20. However, we prefer the illustrated,embodiment because as may be appreciated from Fig. 3, the toggle formed by the back support bracket 16 and the rearward back-support link 18 approaches alignment in the full recline position. In these circumstances, the attach-ment of the control link 30 to the back-support bracket 16, - as illustrated, applie~ a counter-force directly to the back-support bracket 16 to break the togg,le "knee", and assist the return of the back rest to thé upright position.
We conceive it also possible to connect the control link 30 to the rearmost back-support link 18, again with some , re-shaping of the lever 28 to achieve the desired result.
On the other hand, the application of a countermoment directly to the back rest alone, as by pivoting the rearward portion of the seat directly upon an extension of the back-,, -5-~V3t;4t77 support bracket 16, while effective in counterhalancing the back in the setting of an overslung seat-suppart linkage, is undesirable for other overriding reasons, viz., because the rearward movement of the lower end of the back away from the seat incident to recline is undesirable for its "shirt-tail.pulling" effect and also for its failure to provide the lower lumbar support that results from the illustrated linkaye, in which the lower supporting surface of the back rest move~
but little forwardly or rearwardly o the seat during the reclining movement.
Referring in,greater detail to the drawings and par-ticularly Figure.l, it will be seen that-the base bracke~,12 is essentially a length of angle iron with its vertical.flange directed upwardly on the lnner~side of the bracket, ahd having lS at,~i~s rear end an~up~ardly inclined outrigger extension 32.
The horizontal flange of the base bracket 12 is provided with a number...of anchori,n~ holes,34 for securing the.same to a wooden base by means of any suitable fasteners, preferably screws. In each of the drawings, the linkage~is.depicted-:as mounted upon a fixed chair base 10, suggesting its application to an ordinary redlining chair, but it should be understood that the,linkaqe~is equally applicable:to so-called "rocker-recliners" in which case ~he base mounting bracket,12 is secured in the,same f,ashion t,o the racker element instead, of to a fixed base as the drawing~ indicate.
The aforementioned outrigger 32 of thæ base bracket, 12 provides an appropriately.positioned point of attachment for the lower end of the rear back-support link 18~ the upper end of which is suitably pivoted to the lower end of the back-support bracket 16. The forward back-support link 20 is bommerang shaped and-pivote~ at the juncture of its two arms to the upstanding flange of the base bracket 12, and at the 1~}3~4~7 upper end of its rearwardly and upwardly extendin-J arm to ~he lower forward end of the back-support bracket 16. It will be apparent that the two links 18 and 20, constituting together with the base bracket 12 and the back-suppoxt bracket 16 a four-bar trapezoidal linkage, fully determine the path of movement o the back-support bracket 16, which a~ sh~wn by comparison o ~igures 2 and 3, moves forwardly relative to the base bracket 12 as it is rotated counterclockwise by the reclining movement.
- As shown especially in Figure 1, the vertical flanye of the base bracket 12 and the side plate of the back sup-port bracket 16 are in the same plane, the back support links 18 and 20 beLng mounted on the inside surfaces of ~ those brackets. The other, shorter arm 36 of the bommerang- -shaped back-support link 20 engages a stop plate 37 secured ~ to ~h~ under~i~e of the hase bracket 12, and thus aetermines ; the upright or sittLng position of the linkage.
The back-support bracket 16~has an inwardly eXtending ~ flange 38 to provide a mounting seat for the frame of the backrest 1~, holes 40 being provided therein to secure the - back to its suppor~ing bracket by means of screws. The Iowar -~
end of the flange 38, by its contact with the rear back sup-port link l8, provides a stop to determine the fully reclined position (Figure 3).
:
~ ~ The seat support bracket-24 is a downwardly-open channel in its forward portion, thus providing opposed flanges ~or mounting the operating li~kage o a footrest 42. Such .
linkage, ~eing irrelevant to the subject matter shown and claimed, is omitted, and may be any suitable footrest support mechanism operated either by the reclining action of the seat and back, or by separate lever action, as may be desired in a particular application.
r~ .
:; ~7- .
~36~r~7 The rearward, angle portion of ~hc sea~ bracket 24 ¢Fic~ure 1 A) includes a depending vertical inner flange 4~ of yradually increasing depth from front to rear, providiny forwardly of its mid point a ConYenient site for the pivotal atkachment of the forward support link 26. For reasons not relevant here, the : flange 44 has a circular boss stamped outwardly therefrom so that the pivot rivet at the upper end of the link 26 may be flush with the forward surface.of the flange. The more rearward deepest portion of the flange 44 is the point of the pivotal at-tachment of the seat bracket to the lower orward pivot of thebell crank lever 28, while rearwardly of its pivotal attachment to the bell crank, the vertical flange 44 of the seat support bracket recedes upwardly to.a depth commensurate with its , horizontal flange.
The forward portion of the seat bracket 24, as earlier noted, is an inverted channel-whose outer flange 46 is pierced aoaxially with the rivet hole for the:upper pivot of the link 26, to provide a work hole 48 large enough for access by the riveting tool.
20 - Because the seat bracket 24 is mounted outwardly of the ~-baak-support links 18 and 20, and outwardl~ of the bell crank 28 and the control link 30, its rearward portion is shown in broken outline in several of the drawings in order not to obscure those elements of the-linkage.
In order to;provide the necessary moming clearances for the action of the several m~bers of the linkage in the transition from Figure 2 to Flgure 3, relief in depth is provided by offsets in the bell crank lever 28, in the con-trol link 30 as well. Specifically as noted particularly in Figure 1 B~ the body of the bell crank lever 28, a triangular stamping, occupies three planes. At the site of its pivotal attachment to the seat brackPt 24, it is embossed outwardl~
, ......................................................................... ~ ~,,.
~036~77 as at S0, and at the site of its pivotal atkachment to the for-ward back support link 20, it is el~ossed inwardl-y as at 52, leaving its third pivot site 54 in the mid-plane. Clearance for the movement of the'control link 30 is thus provided between the vertical flange 44 of the seat bracket and the ~or~ard back support link 20. The control link 30 itsel is o~set at its upper end to provide clearancé for its passaye over the head o~
the upper pivot rivet of-the back-support link 20.
,~ Because oP the balance achieved in this linkage, it, i5 possible to construct the upholstered seat and arms for at-tachment as an integral unit to the seat bracket 2~. This is pa,rticularly desirable in the rocker-recliner chairs for it , .
not only eliminates the wear and noise resulting.,from movement of the seat within,and rèlative to the arm frames, it also lends .
,~ 15 great'er flexibility of styling as contrasted to chairs of ~ current manufacture having a two-phase reclining movement, - , ,:
i.e., a first rearward shifting of the seat to extend the leg ,- rest to an intermediate so-cailed'"TV" position, essentially ~ without substantially reclining movement of the back. Such ~chairs, by~requiring fixed arm rests against which the oc-cupant can push hLmself and the seat rearwardly, are lim~ted 'in their styling capabilities inasmuch as they cannot satis-~; ~factorily use a T-shaped seat cushion.
~- ~ As earlier indicated, the sitting position of the,, chair is determinéd by the engagement of the,lower arm 36 'of,the forward, boomerang back suppbrt link 20 with the stop ~platP 37 secured to the hori~ontal flange of the base bracket 12. This is shown both in Figure 1 and Figure 2. Particular-ly from Figure 2 it will be,noticed that the support link 26 for the seat is lnclined upwardi~ ,and rearwardly in sitting position so that the occupant'~ ~eight,upon the seat main-tains a compre~sive loading not only upon the support link 26 ,~ ~
- : . .. , . . ~
::~
- . _ g _ , __ -, ~'V3~4q7 , of thç se,at, but also upo,n the,control link 30. It,will further be apparent that each one,of the pivots of the linkaye likewise remains under load in,every conceivable position the~linkage may occup~. This constant loading has tke advantage, as earlier in-~5 dicated, of eliminating clicking noise in the linkage when thesame is used in a rockér-recliner~ i.e./ when the linkage in the position shown in Figure 2 is-rocked back,and forth without rela-~, .
~ tive,movement,of the seat an~ ba¢k of the chair.
, ~, i ~, , , ~ Further with regard to Figures 2 and 3, it is apparent '~10 that as the,:back,l~ is reclinedi its ~ower end, being immediately : adjacent to the ba~k support bracke~.16, moves,forwardly, as doesthe seat.. Th'e center.-of gra~ity of the occupant, different of . course in person$ of dif,ferent stature/ is usually located in the : . lower abdome~.. The position o~ that center,.asi may be appre-cia~ed bY comparison of ~igure$-2 an~ 3, will remain,relatively unchanged between the sitting and the fully reclined positions, and in intermediate.positions a~ well...This tends to provide good.inherent balance,wi~hout the need either o counterbalancing ~ springs,.or of motion-retarders or snubberst such,as are often-: '2Q required either to compensate for over-shifting of body weight,, ~:or to provide artificial retardation,for movement that would ' : otherwise be unduly accçle~ated or abrupt. ~ ",~
The features.of ou~ invention beleived new and'patent-abl~ are-set forth in the'appended claims~
.
- : . .
, .
: ' . ' ~, ~,' ' . . , ::
' - . . : ,~ ~ . . :
~ 1 0
Claims (4)
1. In a reclining chair having a base, a seat, a back, and linkage means at each side of the chair interconnecting said back and seat and mounting the same upon said base for movement relative thereto and to each other from a sitting position to a reclining position, the improvement wherein said linkage means supports the back upon the base for forward shifting movement through a fixed path relative to the base as an incident to re-cline of the back and includes at least one back link extending upwardly from the base to back and pivoted to both for rotation forwardly on the base by the recline of the back, a seat link connecting the forward portion of the seat to the base and being inclined rearwardly and upwardly from the base to the seat when in said sitting position, and a lever pivoted on said back link and connected by a control link to a portion of said chair other than said seat and with respect to which said back link is relatively movable upon the recline of the back, said lever being also pivoted to the rearward portion of the seat to support the seat and to move the seat forwardly relative to the base by the recline of the back.
2. The improvement of Claim 1 wherein said back is supported by two links each pivoted to the base and extending up-wardly therefrom to pivotal connections to the back to form a trapezoidal four-bar linkage with said base and back and wherein said lever is pivoted to the forwardmost one of said two links, and said control link connects said lever to one of said base, said back, or the other of said two links.
3. The improvement claimed in Claim 1 wherein said con-trol link rotates said lever to advance the pivotal attachment of the lever to the seat faster than the pivot of the lever to said back link.
4. The improvement claimed in Claim 2 wherein said lever is a bell crank whose pivot to said forwardmost link is disposed between and above the pivotal connections of the bell crank to said seat and to said control link, and said control link is pivoted to said back.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US374355A US3869172A (en) | 1973-06-28 | 1973-06-28 | Chair reclining mechanism |
| CA213,794A CA1036477A (en) | 1973-06-28 | 1974-11-15 | Chair reclining mechanism |
| DE2459109A DE2459109C3 (en) | 1973-06-28 | 1974-12-13 | Hardware linkage for an armchair |
| JP49142596A JPS5174755A (en) | 1973-06-28 | 1974-12-13 | Rikuraininguisu |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US374355A US3869172A (en) | 1973-06-28 | 1973-06-28 | Chair reclining mechanism |
| CA213,794A CA1036477A (en) | 1973-06-28 | 1974-11-15 | Chair reclining mechanism |
| DE2459109A DE2459109C3 (en) | 1973-06-28 | 1974-12-13 | Hardware linkage for an armchair |
| JP49142596A JPS5174755A (en) | 1973-06-28 | 1974-12-13 | Rikuraininguisu |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1036477A true CA1036477A (en) | 1978-08-15 |
Family
ID=50391586
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA213,794A Expired CA1036477A (en) | 1973-06-28 | 1974-11-15 | Chair reclining mechanism |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US3869172A (en) |
| JP (1) | JPS5174755A (en) |
| CA (1) | CA1036477A (en) |
| DE (1) | DE2459109C3 (en) |
Families Citing this family (26)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4072342A (en) * | 1976-04-20 | 1978-02-07 | Pontiac Furniture Industries, Inc. | Recliner chair |
| US4226473A (en) * | 1978-03-13 | 1980-10-07 | Pontiac Furniture Industries, Inc. | Reclining chair |
| US4492407A (en) * | 1982-07-19 | 1985-01-08 | Syntex (U.S.A.) Inc. | Patient support and transverse motion linkage therefor |
| DE3421274A1 (en) * | 1983-06-16 | 1984-12-20 | Aisin Seiki K.K., Kariya, Aichi | SEAT LIFTER |
| JPS60160910A (en) * | 1984-01-31 | 1985-08-22 | 株式会社タチエス | Seat of vehicle |
| DE8614186U1 (en) * | 1986-05-26 | 1986-07-17 | Drabert Söhne GmbH & Co, 4950 Minden | chair |
| IT206947Z2 (en) * | 1986-06-12 | 1987-10-26 | Pro Cord Srl | CHAIR WITH ARTICULATED BACKREST |
| US4707025A (en) * | 1986-06-26 | 1987-11-17 | Parma Corporation | Rocker recliner |
| JPS6395206U (en) * | 1986-12-11 | 1988-06-20 | ||
| US5217276A (en) * | 1990-10-18 | 1993-06-08 | La-Z-Boy Chair Company | Chair mechanism |
| US5271660A (en) * | 1990-10-18 | 1993-12-21 | La-Z-Boy Chair Co. | Reclining sofa |
| US5292170A (en) * | 1991-08-06 | 1994-03-08 | La-Z-Boy Chair Co. | Recliner assist apparatus |
| FR2692529B1 (en) * | 1992-06-18 | 1994-09-16 | Faure Bertrand Automobile | Improvements to vehicle seats with multiple settings. |
| US5570930A (en) * | 1993-08-09 | 1996-11-05 | La-Z-Boy Chair Company | Recliner chair seat assembly and method of upholstering |
| US5890765A (en) * | 1996-06-07 | 1999-04-06 | La-Z-Boy Incorporated | Health care reclining chair |
| DE19634665A1 (en) * | 1996-08-28 | 1998-03-05 | Jungjohann Thomas | Seating furniture element, in particular upholstered furniture element, with a coupled backrest and seat adjustment |
| US6109694A (en) * | 1999-06-01 | 2000-08-29 | Hon Technololgy, Inc. | Chair with four-bar linkage for self-adjusting back tension |
| AU783829B2 (en) | 2000-09-28 | 2005-12-08 | Formway Furniture Limited | A reclinable chair |
| DE202005010097U1 (en) * | 2005-06-26 | 2006-11-09 | Bock 1 Gmbh & Co. Kg | Synchronous mechanism for the seat-backrest movement of an office chair comprises a base support placed on a chair column, a seat support and a backrest support |
| DE102009059246A1 (en) * | 2009-12-21 | 2011-06-22 | Beuth Hochschule für Technik Berlin, 13353 | Stress-adaptive trained components |
| CN102113781B (en) * | 2011-01-30 | 2012-10-24 | 傅建华 | Chair |
| CA3123791C (en) | 2013-03-15 | 2023-05-02 | Stryker Corporation | Medical support apparatus |
| US10729246B2 (en) | 2017-12-21 | 2020-08-04 | Stryker Corporation | Person support apparatus with shear-reducing pivot assembly |
| US11589678B2 (en) | 2019-01-17 | 2023-02-28 | Hni Technologies Inc. | Chairs including flexible frames |
| DE102019129174B4 (en) * | 2019-10-29 | 2024-10-10 | Grammer Aktiengesellschaft | vehicle seat |
| DE102019131595B4 (en) | 2019-11-22 | 2023-03-02 | Grammer Aktiengesellschaft | vehicle seat |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US799128A (en) * | 1904-07-02 | 1905-09-12 | John F Wilmot | Adjustable reclining-chair. |
| US2240850A (en) * | 1938-10-06 | 1941-05-06 | Floral City Furniture Co | Chair |
| GB724329A (en) * | 1952-04-25 | 1955-02-16 | Albert Ducrot | Improvements in or relating to convertible chairs |
| US2764224A (en) * | 1953-01-28 | 1956-09-25 | Maurer Pierre | Reclining chair with foot rest articulation |
| JPS5016988B2 (en) * | 1971-09-29 | 1975-06-17 |
-
1973
- 1973-06-28 US US374355A patent/US3869172A/en not_active Expired - Lifetime
-
1974
- 1974-11-15 CA CA213,794A patent/CA1036477A/en not_active Expired
- 1974-12-13 JP JP49142596A patent/JPS5174755A/en active Granted
- 1974-12-13 DE DE2459109A patent/DE2459109C3/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2459109A1 (en) | 1976-06-24 |
| US3869172A (en) | 1975-03-04 |
| DE2459109C3 (en) | 1981-02-26 |
| JPS545749B2 (en) | 1979-03-20 |
| JPS5174755A (en) | 1976-06-28 |
| DE2459109B2 (en) | 1980-05-29 |
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